Feeder-ice w



July 17; 1923. 1,462,301

F. W. PARSONS PLATE VALVE UNLOADER File'd Sent. 18 1922 Patented July 17, 1923.

UNITED STATES 1,462,301 PATENT. OFFICE.

FREDERICK W. PARSONS, OF ELMTRA, NEW YORK, ASS IGNOR TO INGERSOLL-RAND COIVIPANY, O1 JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

PLATE-VALVE UNLOADER.

Application filed September 18,1922. Serial No. 588,918.

To all whom it may concern:

Be it known that I, FREDERICK W. PAR- soNs, a citizen of the United States, and a resident of Elmira, county of Chemung, State of New York, have invented a certain Plate-Valve Unloader, of which the following is a specification, accompanied by drawlngs.

more particularly to a plate valve unloader for compressors, by means of whicha plate valve, preferably an inlet valve, is held open for unloading purposes.

The objects of the invention are to secure a simple and efficient device, which will not readily get out of order, for holding aplate valve away from its seat when desired for unloading, and to enable the device to be so constructed that may be conveniently apvalve plate E and the stud F, is inserted in the opening G in the wall H of the cylinder.

A valve cover J is adapted to close the opening in the outer wall Kof the compressor, opposite the plate valve andasuitable stud L carried by the cover J cooperates with the stud F of the plate valve and holds the valve seat C in the opening G In accordance with this invention, the valve cover J is provided with a plurality of piston chambers 0 closed by perforated caps or plugs P to which pipe connections Q may be connected. Pistons R operate in the piston chambers O and are preferably hollow and provided with piston extension S extending outwardly beyond the portions of the valve cover J forming the chambers.

Springs T are preferably adapted to be compressed between the heads of the piston and the ends of the piston chambers, so that upon relieving the fluid pressure, against the pis ton heads, the springs T will retract the pistons.

Each piston is provided with a plunger U and plunger sprin s V, located in the hollow pistons R and hel in position by the plugs This invention relates to plate valves, but

W tending to force the plungers outwardly. The plungers U are adapted to bear upon the valve plate E and hold it from its seat when the pistons R move outwardly in their piston chambers. A portion of an air receiver X is shown connected by the pipe Y to a suitable pressure controlled pilot valve Z, and it is to be understood that a valve of the type shown in United States Patent No. 1,138,278, granted May 4, 1915, to J. H. Castle and W. G. Rogers, may be used, which is so con structed that the valve operates to admit a certain predetermined receiver pressure to an'unloa dingmechanism such as. the plate valve unloader shown herein, until the receiver pressure falls a certain amount below that required to operate the pilot valve, in which case the pilot valve returns to its original position,allowing the pressure chambers of the plate valve unloader to exhaust to atmospheric pressure. I have merely indicated the valve chest 10, the adjustable valve plug 14, and the spring cup 28, corresponding to similar parts similarly numbered in the said patent, it being understood that any other, type of pilot valve may be used in the location indicated by the valve Z and this valveforms no part of my invention.

In the operation of the device, the pistons R and plungers U operate together, and the plungers act directly on the inlet plate valve E. VVhen' thepressure in the receiver X becomes sufiicient to operate the pilot valve Z, allowing fluid pressure to pass to the piston chambers O of the unloader, the resistance of the piston springs T is overcome. The pressure from the receiver X forces the unloader pistons and unloader plungers outwardly until the plungers open the inlet valve. The compressor remains unloaded as long as there is suflicient pressure in the receiver to operate the pilot valve Z. The plunger springs V acting on the plungers, hold the inlet valve E open. during the return stroke of the compressor piston'when unloaded. The piston springs T hold the pistons and plungers away fromthe inlet valve when the compressor is building up pressure in the receiver.

I claim:

1. A plate valve unloader, comprising a plate valve and its seat, stop plate and stud,

adapted to lie in a Valve opening in the cyl-,

inder wall of a compressor, a valve cover over the valve seat having a plurality of piston chambers, hollow pistons in said chambers, and plungers carried by the pistons and adapted to hold the said plate valve open.

2. A plate valve unloader, comprising plate valve and its seat, stop late and stud, adapted to lie in a valve opening in the cylinder wall of a compressor, a valve cover over the valve seat having a plurality of piston chambers, hollow pistons in said chambers, retracting springs adapted to be compressed by the pistons, plungers carried by the pistons and adapted to hold the said plate valve open, and springs in said hollow pistons tending to hold said plungers outwardly.

3. A plate valve unloader, comprising plate valve and its seat, stop plate and stud, adapted to lie in a valve opening in the cylinder wall of a compressor, a valve cover over the valve seat having a stud for holding the plate valve structure to its seat in the wall of the compressor, a plurality of piston chambers in said valve cover, hollow pistons in said chambers, retracting springs within the said chambers adapted to be compressed by the pistons, plungers carried by the pistons and adapted to hold the said plate valve open, and springs in said hollow pistons tending to hold said plungers outwardly. y

In testimony whereof I have signed this specification.

FREDERICK W. PARSONS. 

